The French network of diagnostic laboratories for mitochondrial diseases (MitoDiag) has published the results of a clinical and genetic study (panel, WGS and/or WES on the nuclear genome) of around 2,000 patients suspected of having a primary mitochondrial disease (PMD). The authors observed:
- pathogenic variants in 397 patients (newborn to 81 years), 74% of whom were children, representing the largest cohort of its kind described to date;
- 322 patients with MMP and 75 with an MMP picture, but of non-mitochondrial genetic origin;
- 172 different genes affected, 501 genetic variants (253 new);
- more common involvement of genes linked to oxidative phosphorylation in children, and mitochondrial DNA maintenance in adults;
- within MMPs, a greater frequency of Leigh syndrome in children (60 out of 294), and chronic progressive external ophthalmoplegia in adults (36 out of 103).
The researchers also propose a decision tree to guide doctors in their diagnostic strategy for these diseases.
